Eduprobe
Question:
If the coefficients of x³ and x⁴ in the expansion of (1+ax+bx²)(1-x)¹⁸ in powers of x are both zero, then (a,b) is equal to:
(16,2513)
(14,2513)
(14,2723)
(16,2723)
Solution:
1(1x)18+ax(1x)18+bx2(1x)18